I recently read an article in which the article stated one of the issues with drag trains is the stress put on couplers and the fact that when they put the drag trains together consideration has to be taken not to over stress the coupler , especially those near the head end. The methods described in the article, to solve the problem was to add mid and end train engines which of course have there own issues. Now for the question. Over the years I have read articles on someone cursing one model railroad coupler manufacture or another . Is it possible that model railroad couplers suffer the same stresses , on a different scale than real life couplers, if the drag or consist is not built properly thus the broken coupler issues ???
Physics is physics. Yes, pretty much all the same forces apply. We don't run our cars loaded, and our engines have relatively low tractive effort, but the whole force required to pull the train does end up on that first coupler joint.
If real railroads used cheap plastic couplers, though, they would experience the same high failure rates that modelers who don't use Kadees see.
If you're not going to equip everything with Kadees, at least do your engines. That's where you will always have the maximum force on a train.
It takes an iron man to play with a toy iron horse.
To some degree this is probably the case, though it seems to be an issue more for the plastic "Kadee compatible" couplers rather than for the true Kadees (which are all-metal)...
-Dan
Builder of Bowser steam! Railimages Site
When I started running 20 to 30' trains through hills and curves, the realization of needing another step or more of improvement was obvious with the multiple break aparts. Coupler alignment to within .005" became one goal(not always there though), coupler movement allowing swing but no droop and a conversion to Kadees. I like the original head Kadees, not the new scale heads for these longer trains, particularly with longer cars(which have more vertical coupler movement with grades). I particularly like the shelf couplers as is prototypical for newer locos, psgr cars and tank cars.
The plastic couplers just don't hold up under heavy loads over time. Besides being plastic a lot of those couplers don't keep the nuckle tightly closed, unless they use a coil spring. And then due to the flexibility of the plastic those coil springs are more easily lost.
We may have break aparts today, but it's almost always traceable to an upset condition or poor train handling.
Richard
I discovered Kadee couplers in the mid 80s, when I built my first layout, and have used nothing else since. Anything that doesn't have Kadees installed from the factory, gets replace with a real one. Some cars/locos take a little more work than others.
Marlon
See pictures of the Clinton-Golden Valley RR
We have run 100+ loaded hoppers on coal drags at the club. Yes, playing not during any ops session. Have used pushers and mid helpers, but even pulling the string from head end have never had an issue w/ failure of a "#5" Kadee. I imagine you could experience a defective one or bad mounting and break apart. I generally will pull a B&O coal drag with 35-40 hoppers. This is why when fitting my F units w/ the 30 series I placed a metal instead of plastic knuckle.
Modeling B&O- Chessie Bob K. www.ssmrc.org
bogp40,
I always thought the plastic series coupler had a metal knuckle and a plastic shank.
Will
yougottawanta I recently read an article in which the article stated one of the issues with drag trains is the stress put on couplers and the fact that when they put the drag trains together consideration has to be taken not to over stress the coupler , especially those near the head end. The methods described in the article, to solve the problem was to add mid and end train engines which of course have there own issues. Now for the question. Over the years I have read articles on someone cursing one model railroad coupler manufacture or another . Is it possible that model railroad couplers suffer the same stresses , on a different scale than real life couplers, if the drag or consist is not built properly thus the broken coupler issues ???
Not really a problem with metal Kadee couplers. The coupler boxes will pull off the cars before the couplers fail. I have run 100 car trains (in HO) at the club and coupler failure is not the problem. Derailment, and insufficient power will trip you up before coupler failure sets in.
David Starr www.newsnorthwoods.blogspot.com
bogp40 We have run 100+ loaded hoppers on coal drags at the club. Yes, playing not during any ops session. Have used pushers and mid helpers, but even pulling the string from head end have never had an issue w/ failure of a "#5" Kadee. I imagine you could experience a defective one or bad mounting and break apart. I generally will pull a B&O coal drag with 35-40 hoppers. This is why when fitting my F units w/ the 30 series I placed a metal instead of plastic knuckle.
bogp40
I assume you are running DCC ? How do you get the helpers and pushers to run with the head end. How do you adjust for things like slack, different locomatives ? Do you run a consist with steam and diesal ?
yougottawanta bogp40: We have run 100+ loaded hoppers on coal drags at the club. Yes, playing not during any ops session. Have used pushers and mid helpers, but even pulling the string from head end have never had an issue w/ failure of a "#5" Kadee. I imagine you could experience a defective one or bad mounting and break apart. I generally will pull a B&O coal drag with 35-40 hoppers. This is why when fitting my F units w/ the 30 series I placed a metal instead of plastic knuckle. bogp40 I assume you are running DCC ? How do you get the helpers and pushers to run with the head end. How do you adjust for things like slack, different locomatives ? Do you run a consist with steam and diesal ?
bogp40: We have run 100+ loaded hoppers on coal drags at the club. Yes, playing not during any ops session. Have used pushers and mid helpers, but even pulling the string from head end have never had an issue w/ failure of a "#5" Kadee. I imagine you could experience a defective one or bad mounting and break apart. I generally will pull a B&O coal drag with 35-40 hoppers. This is why when fitting my F units w/ the 30 series I placed a metal instead of plastic knuckle.
We do runn DCC, however when we will play like this, A single operater: hold helpers on DT400 throttle as separate on left hand knob, MUed head end power as usual on right knob. If 2 operators, we will run 2 "engineers" and w/ 2 throttles. Takes practice just like the real thing. The 2nd engineer needs to control his power and watch the coupler slack or push. Very interesting way to have some fun. Should give it a try. Does get very sticky with 100 cars and or a mid train helper.
wholeman bogp40, I always thought the plastic series coupler had a metal knuckle and a plastic shank.
If you look closely at the plastic knuckle couplers, you'll see that the whole coupler is made of plastic. The only metal part is the uncoupling pin. And I've found that the uncoupling pin on the plastic couplers must have a lower steel content in it; magnetic uncouplers don't pull them to the side as far as the Kadees.
I don't believe it does, but the weak part is the pivot @ the knuckle as Marlon points out. These are still extremely strong couplers though. Half of my Stewart Fs (passenger ) still have the origional 30series #450 close coupling. 12 Walther's passenger passenger cars do need some pulling power even w/ axles oiled.